berry

Why Is My Dishwasher Not Draining?

by the Berry team · Updated

Standing water in a dishwasher is usually a clogged filter, a clogged garbage disposal or drain hose, or, right after a new disposal install, a knockout plug that was never removed. Those are free or cheap to fix yourself, and only if they all check out is a failed drain pump likely, which typically runs $150-$350 to replace with a technician.

Likely causes and what they cost to fix

Ordered roughly from most to least common. Work through the checks in order before calling.

Clogged filterDirty water sits in the bottom, dishes come out gritty, and the filter under the bottom rack is caked with food.DIY$0Pro$100-$200 for a service call
Clogged garbage disposalIf the dishwasher drains through a disposal: water backs up when the disposal is full or has not been run.DIY$0Pro$100-$250
Knockout plug in a new disposalThe dishwasher stopped draining right after a new disposal was installed.DIY$0 with a screwdriver and hammerPro$100-$200
Kinked or clogged drain hoseThe hose under the sink is bent behind the dishwasher, or clogged where it connects to the disposal or drain.DIY$0, or $10-$25 for a new hosePro$100-$250
Clogged air gapIf you have a small cylinder on the sink deck next to the faucet: water spills out of it during draining.DIY$0Pro$100-$200
Failed drain pump or check valveEverything above is clear, and you hear a hum or nothing at all when it should drain.DIY$30-$100 for the partPro$150-$350
Control board or sensorThe drain cycle never starts, or the dishwasher shows an error code.DIYNot recommendedPro$200-$500

Ranges are typical US prices and vary with your region, your home, and the season. A pro quote for your exact job beats any range.

Check these in order

  1. Bail out the water. Turn off the dishwasher, then use a cup and towels to remove the standing water so you can reach the filter.
  2. Clean the filter. Pull out the bottom rack. Most dishwashers have a cylindrical filter that twists out. Rinse it under hot water and scrub with a soft brush. Wipe out the sump area underneath.
  3. Run the disposal. If the dishwasher drains through a garbage disposal, run it with cold water for 30 seconds. A full disposal blocks the dishwasher drain.
  4. Check for a knockout plug. If the disposal is new, a plastic plug inside the dishwasher inlet may never have been knocked out. Unplug the disposal, remove the hose, and tap the plug out with a screwdriver.
  5. Check the drain hose. Look under the sink for kinks. Disconnect it at the disposal or drain and check for clogs.
  6. Clean the air gap if you have one. Pull off the cover and clear any debris inside.
  7. Run a short cycle and watch whether it drains.

The high loop and why it matters

The drain hose should rise up and loop as high as possible under the counter before it drops to the disposal or drain, or go through an air gap. That loop keeps dirty sink water from flowing back into the dishwasher. If the hose runs flat along the cabinet floor, dirty water can backflow, which causes poor draining and smells. See why a dishwasher smells.

If the sink backs up too

If the kitchen sink is also slow or backing up, the clog is likely in the shared drain line, not the dishwasher. See why a drain is slow and how to clear it. If the disposal hums but will not spin, see how to reset a garbage disposal.

Replacing the drain pump

If everything is clear and the dishwasher still will not drain, the pump is the usual suspect. On many models it is reachable from underneath after removing the kick plate or by pulling the dishwasher out. It is a manageable DIY job for some people, but it means disconnecting water and power and dealing with residual water. On an older dishwasher with rusted racks or other problems, a pump replacement may not be worth it. See how long appliances last.

When to call a pro

  • The filter, disposal, hose, and air gap are clear and it still will not drain.
  • Water is leaking from under the dishwasher onto the floor.
  • The kitchen sink and other drains are backing up too.
  • The dishwasher shows an error code you cannot clear, or the drain pump hums without moving water.

What makes it worse if you wait

  • Standing water grows bacteria and odors quickly.
  • A clogged filter sends grit back onto dishes and makes the pump work harder until it fails.
  • A dishwasher that drains slowly can leak at the door or from under the unit, damaging cabinets and subfloors.

Common questions

Is it normal to have a little water in the bottom of a dishwasher?

A small amount of water in the sump area under the filter is normal on many dishwashers. Water pooling up across the floor of the tub is not, and usually means a clog.

How do I unclog a dishwasher that will not drain?

Remove the standing water, clean the filter, run the garbage disposal if you have one, check the drain hose for kinks or clogs, and clean the air gap if you have one. These steps fix most draining problems.

How much does it cost to fix a dishwasher that will not drain?

Most fixes are free. A new drain hose costs about $10-$25. Replacing a drain pump typically costs $150-$350 with a technician, and control board repairs can run $200-$500.

Why did my dishwasher stop draining after a new disposal was installed?

The installer likely left the knockout plug in the disposal dishwasher inlet. Unplug the disposal, remove the dishwasher hose, and knock the plug out with a screwdriver and hammer, then remove the plug from inside the disposal.

Not sure that's your problem? Snap a photo and Berry will tell you what it is and what it should cost.

Try Berry freeDownload on the App Store

Keep reading